Ptolemy Philopator of Egypt had died in 549. Philip and Antiochus,
the kings of Macedonia and Asia, had combined against his successor
Ptolemy Epiphanes, a child of five years old, in order completely
to gratify the ancient grudge which the monarchies of the mainland
entertained towards the maritime state. The Egyptian state was to be
broken up; Egypt and Cyprus were to fall to Antiochus Cyrene, Ionia,
and the Cyclades to Philip. Thoroughly after the manner of Philip,
who ridiculed such considerations, the kings began the war not merely
without cause but even without pretext, "just as the large fishes
devour the small."

The allies, moreover, had made their calculations
correctly, especially Philip. Egypt had enough to do in defending
herself against the nearer enemy in Syria, and was obliged to leave
her possessions in Asia Minor and the Cyclades undefended when Philip
threw himself upon these as his share of the spoil. In the year in
which Carthage concluded peace with Rome (553), Philip ordered a fleet
equipped by the towns subject to him to take on board troops, and to
sail along the coast of Thrace.